The cost of cleaning up an abandoned uranium mine in northern Saskatchewan is expected to exceed $250 million, more than 10 times the original estimate – and the provincial and federal governments are divided on how the burden will be shared.

Located on the northern shore of Lake Athabasca near Uranium City, about 800 kilometres north of Saskatoon, the Gunnar uranium mine was abandoned in 1964. The site remained littered with radioactive tailings, asbestos-laced buildings and other waste for more than half a century.

The original mine operator, Gunnar Mining Limited, no longer exists.

In 2006, the federal and provincial governments signed an agreement to rehabilitate the site and reduce further ground and water contamination. The project was originally estimated to cost no more than $24.6 million and take 17 years, according to Natural Resources Canada documents.

The cost of environmental and engineering studies, the remoteness of the site and the complexity of cleaning up radioactive areas caused the budget to expand, according to the Saskatchewan Research Council (SRC), which the provincial government contracted to clean up the site.

The total project budget is now estimated to be $268 million, of which $13 million is earmarked for rehabilitating other contaminated sites in the area, according to the provincial government.

The initial estimate of $24.6 million is best described as a startup budget – funds intended to pay for preparatory work and the extensive environmental and engineering studies necessary for cleaning up nuclear sites, the provincial Ministry of the Economy’s deputy minister Laurie Pushor said.

“That lets you come to a place where you can put a much more detailed strategy together, and with that in mind you’re able to build a much more accurate estimate of what it’s going to cost,” Pushor said. “So those funds got the ball rolling, if you will, and allowed us to do the detailed work.”

The uranium deposit at the site was discovered in 1952. Production began three years later and continued until 1963.

When the mine was operational, its facilities included open pit and underground mines, a uranium mill, two acid plants and various ancillary buildings.

Three tailings deposits totalling 4.4 million tonnes and a large waste rock pile eventually accumulated on the site.